The objective is the in situ study of: 1) intracellular enzyme kinetics in ref. to spontaneously or chemically induced malignant transformation, 2) the intracellular interactions of carcinogens. Microspectrofluorometry allows the topographic scan of dynamic metabolic changes (e.g. NAD(P) reversibly yeilds NAD(P) transients) due to microinjection of metabolities (e.g. glucose-6-P, glucose-1-P, 6-phosphogluconate) into malignant cells (e.g. EL2 ascites and L), paired lines of normal vs. transformed cells. The same approach can demonstrate the localization of carcinogens. The transient rise or decay halftimes were first evaluated in carcinogen-free cells by mathematical approximation (e.g. difference of two exponentials for transients, power laws for rates). The synchronous activity of cell compartments (e.g. cytoplasm vs. nucleus) in ref. to function demand (e.g. ATP trap, metabolizable hydrocarbons, barbiturates, aflatoxins) was detected. The cell fluorescence spectrum was resolved in free vs. bound NADH, flavins, with differing patterns in ascites, melanoma or sarcoma lines. In benzpyrene-treated EL2 or L cells highly fluorescent metabolites (or interactions) precede low or nonfluorescent metabolities. In EL2 cells these phenomena are detected after injection of substrate leading to formulate of NADPH, in the L cell they occur spontaneously but may be accelerated by substrate. The current goals are to use transient parameters for studies of biochemical systems in normal vs. spontaneously transformed fibroblasts (e.g. NCTC 9197-9195) or cells submitted to challenges (e.g. carcinogens, growth with various substrates, agents affecting organelle function). Fluorescence spectra of carcinogen (or metabolite treated cells) will be recorded in a new high spectral resolution (e.g. approximately 1 nm) microspectrofluorometer. A combined topographic and spectral approach should identify the dynamic topography of different cell lines, and the effects thereupon of spontaneous transformation or carcinogens, as well as the interactions or metabolization undergone by the carcinogens in localized cell regions.